Method of combining leather and caoutchouc



UNITED STATES-PATENT OFFICE.

ROBERT MEYER, F HA NN OVER, GERMANY.

METHOD OF COMBINING LEATHER AND CAQUTGHOUC.

No Drawing. Applicatibn filed October 19, 1925, Serial No. 63,548, andin Germany August 1, 1928.

:My invention refers to means for combinabove described, whereupon it ismixed with ing leather with caoutchouc. It is an object a thinly fluidcaoutchouc solution to form a 45 of my inventionto produce suchcombinapnlp which is then carefully kneaded and tion in a more.eificient manner than was dried at an elevated temperature until the vhitherto possible. material has obtained a satisfactory adhe- Incombining leather with caoutchouc care sive power. has been taken toemploy air dried leather, TVVith the mass thus obtained plastic prod 6that is leather dried at the air or in the sun, nets of different kindscan be produced.

\ inasmuch as leather laden with moisture will Although in consequenceof the preheatnot enter into an intimate and stable coming of theleather a stable combination with bination with caoutchouc and on beingvulcaoutchouc can be produced, the-stability of canized will becomebrittle. It is however the products is increased if they are sub-' 55'Well known that the use of air dried leather jected to vulcanization,preferably after adddoes not altogether obviate the difliculties ingsulphur, either in the cold or at an eleencountered in combining thesetwo sub? vated temperature.

stances. If it is for instance intended to treat In accordance with thepresent invention macerated leather chips, vulcanization at an 60 theleather, which may be air dried, is subelevated temperature may bedispensed with, jected to a further-drying treatment, prefif it ishowever desired to produce soles,

erably by heating it in dry air, for instance heels or the like forshoes or a floor coverin' an air dryer during about twenty-four ing, itis preferable to resort to hot vulcanihours to about 50 C. andpreventing it zation inasmuch as the final product thus ob- 65 fromcoming in contact with moist airunt il tained is more durable thanleather. The it is combined with the caoutchouc. To thisvulcanization-can be efiected in such cases at 55 end the leather thusdried is either stored high temperatures inasmuch as there is no underthe exclusion of air or the combinadangerrof the final product gettingbrittle. tionwith caoutchouc is effected immediate- For I haveascertained that brittleness is 7 ly after the leather has beenwithdrawn from merely caused by a moisture content of the the air dryer.In this manner the absorpleather.

tion of moisture can be prevented. I wish it to be understood that- I donot Preferably leather dried according to the desire to be limited tothe actual sequences present invention is, immediately after the ofoperations, proportions and other details 7 drying operation has come toan end, imabove described for obvious modifications mersed in a rubbersolution, that is a soluwill occur to a person skilled in the art.

tion of caoutchouc in petrol,- whereby the I claim e pores of theleather are closed so s t The method of combining leather and preventthe admission of moisture. caoutchouc comprising the step of drying 80In practicing my invention I prefer emthe leather for about 24 hours atabout ploying Waste leather and preferably the (3., taking care toprevent access of air to pieces of leather are comminuted bv maceratheleather thus dried, and treating same tion or. b grinding, whereupon thedust is with a solution of caoutchouc. 1 removed by sieving and thefibrous or pul- In testimony whereof I aflix my signature. verulentmass. is 'now dried in the manner ROBERT MEYER.

